Cleaning machine



June 25, 1963 A. c. scHouw ETAL. 3,

CLEANING MACHINE Filed Nov. 25, 1960 l 2 Sheets-Sheet 1 INVENTORS June 25, 1963 A. c. scHouw ETAL.

CLEANING MACHINE 2 Sheets-Sheet 2 Filed NOV. 25, 1960 INVENTORJ /9 wu, c. 526 0 0 y oaferl A7 5!! United States Patent f 3,094,999 CLEANING MACHINE Arthur C. Schouw, Detroit, and Robert R. Mosher, Utica, Mich., assignors to Ferro-Fab, Inc., Fenton, Mich., a corporation of Michigan Filed Nov. 25, 1960, Ser. No. 71,743 1 Claim. (Cl. 13.4--132) This invention relates to a machine for cleaning articles and more particularly to a machine for cleaning rigid articles such as may be formed from metal, wood or plastic, which employs a fluid cleansing medium.

The present invention falls within the class of devices which utilize a fluid to impart mechanical energy to the films of .oxide, dirt, lubricants or other foreign matter which are found on the exterior surfaces of rigid articles in order to separate these films from the articles surface. Devices which impart vibrations of a sonic or supersonic frequency to a fluid medium in order to transfer energy to undesirable surface films are an example of this type of machine. They employ a generator imbedded within the fluid medium which is excited to vibrate at a particular frequency. The fluid acts to carry and transfer this energy to all of the immersed surfaces of an article to be cleaned. Such devices have found extensive use in precision industries where it is necessary to obtain articles with film free surfaces.

The present invention also operates by transferring mechanical energy from a fluid medium to immersed articles. However, the energy is imparted to the fluid in the form of unidirectional velocity and temperature rather than the oscillatory fluid velocity such as is employed in ultrasonic cleaning devices. This energy is similarly transferred to the article to be cleaned in order to mechanically remove foreign matter which coats its immersed surfaces.

In a preferred embodiment of the invention, the articles to be cleaned are disposed in an upright cylinder. A fluid, which may utilize various solvents, anti-foaming agents and other additives is heated to a controlled temperature externally of the cylinder and then pumped at a controlled velocity through a series of nozzles which inject it into the cylinder along tangential lines. The

.velocity and direction of the admitted fluid are such as to cause the free surface of the fluid to form a vortex within the cylinder. The articles to be cleaned are supported within this vortex so that interaction with the fluid transfers energy to their surfaces which tends to remove undesirable films. The energy of the fluid vortex may also be utilized to move the parts being processed through the cylinder.

While the mechanism of the interaction between the fluid and the articles is not fully understood, it is believed that cavitation occurs at points within the fluid vortex where the fluid velocity and temperature fall within certain ranges. Cavitation constitutes the creation of a void within the fluid caused by the liberation of oxygen from the fluid at low vapor pressure. Cavitation volumes are capable of exerting local forces greatly in excess of those which generate the cavities. Therefore, cavitation is a source of great difficulty in propeller blades of ships where the phenomenon may cause the metal of the blades to become corroded and pitted. In the present invention, it is believed that the formation of cavities may be controlled by varying the injection velocity and temperature of the fluid medium in such a way as to carefully impart the cavitation energy to the parts to be cleaned.

Other objects, advantages and applications of the present invention will be made apparent by the following detailed description of a preferred embodiment of the FIGURE 1 represents a perspective view, broken away at certain places, of a preferred embodiment of the present invention;

FIGURE 2 is a plan view of the device;

FIGURE 3 is a cross-sectional plan view of the tower of the preferred embodiment taken along line 3-3 of FIGURE 1; and

FIGURE 4 is a cross-sectional elevation view. taken along line 4-4 of FIGURE 2.

The preferred embodiment of the cleaning machine is centered about a cylindrical tank 10 which may be formed of sheet steel. The top of the tank is partially covered by an annular plate 12 extending inward radially from the edge of the cylinder -10 and having a large central hole. The edges of the plate 12 adjacent to the hole are bent downwardly radially as at 14. The cover 12 is preferably removable.

Two injection orifice manifolds 16' and 18 encase the cylinder 10 at points at its lower end and its lower mid section respectively. The two manifolds 16 and 18 are identical and FIGURE 3, which represents a cross section through the manifold 18, is also typical of the manifold 16. The manifold 18 comprises an outer wall 20 and an inner wall 22 which is the wall of the cylinder 10 at the cross section. At four points equally spaced about the inner wall 22, there exists slots 24 which extend partially through the height of the manifold 18 and which constitute vertical separations of approximately A3 width in the walls. The slots 24 are formed with the counter-clockwise edges of the wall sections 22 extending inwardly of the clockwise edge of the adjacent sections as viewed in FIGURE 3. This gives the slot a directional quality and makes it accessible to fluid circulating in the manifold 18 in a counter-clockwise direction. Fluid is admittedto the manifold 18 through a pipe coupling 26 disposed at a tangential projection 28 of the manifold 18.

The lower end of the tank is enclosed by a downwardly concave domed section 32. The diameter of the dome is slightly less than that of the cylinder and an end section 34 connects the edge of the cylinder 10 with the outer diameter of the dome 32.

A central nozzle 36 comprising a short section of pipe propects through a central hole in the doomed section 32 and acts as an outlet for fluid in the cylinder 10 as will be described subsequently.

The cylinder 10 is supported at its lower end on a tank section 38 which in turn rests on a welded base 40. The tank section 38 includes a vertically raised portion 40 which has a door 42.

A pair of electrical immersion heaters 44 are disposed horizontally along the bottom of the tank 38. The external connections of these heaters are not shown but will be generally described subsequently.

The tank section 38 connects to a sump section 46 which shares one common wall with the section 38 and is of a height equal to the raised section 40. An opening between the tank sections 38 and 46 is occupied by a filter screen 48. A door 50 at its upper end gives access to the section 46.

An electric motor driven pump 52 has inlet 26 to the manifold 18 and the analogous input to the manifold 16. I The embodiment of the invention being described is intended to clean small ball bearings. It is therefore necessary to provide means for feeding bearings into the cleaning area and removing them from the area. Before describing such means, it should be understood that the part retaining and feeding means is dependent on the part to be cleaned and widely dissimilar means might be provided for parts of different shape and size.

Patented June 25, 1963 The ball bearings are moved upwardly through the cylinder on a spiral track 54 attached to the inner Wall of the cylinder. The track 54 is formed of small diameter tubing; however, the ball bearings do not circulate within the tubing but rather move in the angular track formed between the inner wall of the cylinder 10 and the upper edge of the outer wall of the tubing adjacent to the cylinder wall. Tubing is simply used because it may be readily formed into a spiral and still retain uniform angularity with respect to the cylinder wall.

Operation To prepare the units for use, the tanks 38 and 48 are first filled with a fluid medium which may, for example, comprise a 2% by weight aqueous solution of any commercially available detergent. The exact composition of the solution is dependent upon the nature of the undesirable film on the articles to be cleaned. The solution is placed in the tanks 38 and 48 to a level slightly below the lower end of the drain pipe 36.

The heating elements 44 are then used to bring the solu tion to a temperature which is also dependent upon the exact nature of the article to be cleaned and its film. By way of example this temperature may be 140 degrees Fahrenheit. A thermostatic device (not shown) is used to control the electrical input to the heaters 44 and thereby maintain the solution at such predetermined temperature. When this temperature has been reached, the pump 52 is energized and it acts to draw fluid from the sump tank 48 and inject it into the cylinder 10 through the manifolds 16 and 18. A typical injection pressure may be 45 pounds per square inch. This pressure causes the fluid to be circulated through the manifold '18 in a counter-clockwise direction as viewed in FIGURE 3 and causes it to be injected into the cylinder through the slots 24. Since this injection is tangential to the cylinder and at a relatively high pressure, the fluid within the cylinder 10 is maintained in rotation and as the cylinder begins to fill the free fluid surface assumes a vortex shape as is indicated by the dotted line 56 in FIGURE 4.

The fluid volume begins to build up near the edge of the cylinder and as more fluid is injected it moves upwardly until an equilibrium point is reached where the bottom of the vortex feeds fluid into the drainpipe 36 at the same rate it is being injected through the slots 24. Gate valves 58 which are disposed at the inlets 26 to the manifolds 16 and 18 are used to control the pressure of injection.

The ball bearings to be cleaned are poured into the cylinder 10 through the top hole in the cover 12. The force of the rotating fluid vortex causes them to become aligned between the top edge of the tubing spiral 54 and the adjacent wall of the cylinder 10. The fluid force also moves them up the spiral 54 in regular order. While 1 moving up the spiral, they are subjected to the cleaning touched by hand.

Although the exact mechanism of the cleaning reaction isnot fully understood, it has been determined that through use of a cylinder approximately 40 inches high and 20 inches in diameter and the temperatures and pressures previously indicated extraordinary and unexpected cleaning results are obtained upon the articles passed through the fluid vortex.

- Having thus described our invention, we claim:

In a cleaning machine having 'a vertical cylindrical chamber, means for injecting fluid tangentially into the lower end of the chamber so as to create a fluid vortex therein, and drain means for said chamber, the improve ment which comprises a spiral parts track disposed along the inner side of said chamber and means for introducing parts at the lower end of the track which may be moved along the track under the forces of the fluid vortex.

References Cited in the file of this patent UNITED STATES PATENTS 654,647 Koppelmann July 31, 1900 858,522 Low July 2, 1907 1,741,329 Montgomery Dec. 3 1, 1929 1,778,620 Barta Oct. 14, 1930 2,471,506 Wiswall May 31, .1949 2,548,100 Oulligan Apr. 10, 1951 2,614,316 Daily Oct. 21, 1952 

